Looking for a little advice and also hopefully some education 
Have recently bought a flat (for which warranty period has expired) which has two bathrooms that were delivered as 'pods' (assembled fully offsite and slotted in when the building was built). They have all sorts of problems (including loose floor tiles, but that's a question for another forum!). One is that none of the heated mirror panels have ever worked. Each bathroom has two opening bespoke mirror cabinets, each with an incoming connection to a demister pad within the assembly. Impossible or highly unlikely that all four have failed together, so I suspected installation error.
There is a removable panel next to each side of each cabinet within which there is a 240V feed coming in, triggered by the lighting sensor, that splits into three - two connections go to 12v LED drivers that power various led mood lights around the cabinet and one goes to another type of 12v transformer and on to the feed for the demister pad. After a bit of diagnosis (swapping the transformer twice and then finally realising that the wires from the demister pad are blue and brown...) I believe I've figured out the issue - they are 240V pads not 12V pads. A test connection straight to mains feed, bypassing the 12v transformer, leads to them heating up correctly...
Next comes the education piece, or where I'm likely to seek a professionals assistance - earthing. The mirrored cabinet doors have a metal edging and all the installation instructions I've read form the various manufacturers of demister pads mention that this should be earthed and in addition if the mirror has a foil backing, this should be earthed... I can see no earthing from either part of the mirror/cabinet-door, although there is an earth available in the 240v feed.
So my questions are:
1) Even if the mirror pad was incorrectly thought to have been a 12V model, is the lack of earthing surprising / concerning? worth adding that the substructure of the doors is all board, with metal edging, rather than solid metal.
2) Mirror pads in general all seem to be double insulated, so why is an earth advised/required when the mirror has a metal edging?
3) Finally, the separately recommended earthing for the potential capacitive effect from the foil backing, I assume this is a mild discharge risk rather than a mains shock risk?
I'm not going to connect the pads straight to the mains if there's any kind of risk - but would like some better understanding before calling in help.
thanks a lot!
Have recently bought a flat (for which warranty period has expired) which has two bathrooms that were delivered as 'pods' (assembled fully offsite and slotted in when the building was built). They have all sorts of problems (including loose floor tiles, but that's a question for another forum!). One is that none of the heated mirror panels have ever worked. Each bathroom has two opening bespoke mirror cabinets, each with an incoming connection to a demister pad within the assembly. Impossible or highly unlikely that all four have failed together, so I suspected installation error.
There is a removable panel next to each side of each cabinet within which there is a 240V feed coming in, triggered by the lighting sensor, that splits into three - two connections go to 12v LED drivers that power various led mood lights around the cabinet and one goes to another type of 12v transformer and on to the feed for the demister pad. After a bit of diagnosis (swapping the transformer twice and then finally realising that the wires from the demister pad are blue and brown...) I believe I've figured out the issue - they are 240V pads not 12V pads. A test connection straight to mains feed, bypassing the 12v transformer, leads to them heating up correctly...
Next comes the education piece, or where I'm likely to seek a professionals assistance - earthing. The mirrored cabinet doors have a metal edging and all the installation instructions I've read form the various manufacturers of demister pads mention that this should be earthed and in addition if the mirror has a foil backing, this should be earthed... I can see no earthing from either part of the mirror/cabinet-door, although there is an earth available in the 240v feed.
So my questions are:
1) Even if the mirror pad was incorrectly thought to have been a 12V model, is the lack of earthing surprising / concerning? worth adding that the substructure of the doors is all board, with metal edging, rather than solid metal.
2) Mirror pads in general all seem to be double insulated, so why is an earth advised/required when the mirror has a metal edging?
3) Finally, the separately recommended earthing for the potential capacitive effect from the foil backing, I assume this is a mild discharge risk rather than a mains shock risk?
I'm not going to connect the pads straight to the mains if there's any kind of risk - but would like some better understanding before calling in help.
thanks a lot!
